Almost every driver has confronted the task of changing a flat tire. This common occurrence usually involves the steps of removing a properly inflated spare wheel/tire from storage, lifting the vehicle with a jack, removing wheel nuts with a wrench, replacing the flat tire with the spare, replacing the wheel nuts, lowering the vehicle back down, and stowing the flat. This can be a dirty, difficult, and even dangerous job. Mud and dirt, rusted and impossibly tight lug nuts, the lifting of heavy spares and flats and the danger of jack failure are all unpleasant, but common, aspects of changing a flat tire.
Various attempts have been made at providing a suitable substitute for the automobile spare tire and for the usual apparatus and method for replacing a flat tire with a spare.
An alternative to the bulky full-size pneumatic spare tire currently in common use is the smaller and lighter temporary spare intended only to allow the vehicle to be driven long enough to reach a gas or repair station. While this concept reduces the weight and size of the spare, elevation of the vehicle and removal of the lug nuts and flat are still required.
A further development has been to provide a temporary spare capable of being mounted on the face of a wheel without the necessity of removing that wheel; see for example U.S. Pat. Nos. 3,866,978, 4,350,394, 4,708,400, and my own U.S. Pat. No. 3,770,323. My earlier patent discloses a spare tire assembly having an eccentric camming section and two semi-circular sections, which sections are adapted to be bolted to the face of the already-installed wheel; i.e., the wheel with the flat tire. Installation requires bolting the eccentric section and one of the semi-circular sections to the flat wheel, moving the vehicle to ride up the rim of the eccentric onto the rim of the full-radius, semi-circular section, stopping the vehicle with the eccentric in a top-most position, and replacing the eccentric with the second semi-circular section.
The principal advantages of my earlier invention are (1) elimination of jacking and the need to remove the wheel with the flat tire, and (2) reducing the normal spare to several smaller, lighter sections which are more easily stored and handled.